Eudora Nicknames/Address Book File Structure

This page is still under construction. In particular, note that some of the details surrounding Eudora's Nicknames and Address Book are changing with Eudora 3.0, especially the way that the Real Name associated with a Nickname is handled. Now that Eudora 3.0 has been released, I'll see about updating this information to reflect the changes.

Why should I care?

You don't have to, but many people want to know about the structure of the Eudora Nicknames (Address Book in Eudora 3.0) file because they want to import addresses from a database or from another mail program. If you want to convert from another mail program's address book, first take a look at the conversion utilities that have already been written. It could save you some time and trouble. Also, your success at using one of these utilities to convert from Eudora Nicknames/Address Book file to something else is determined in part by the format you use in your Eudora Nicknames/Address Book file.

What is the format?

The easiest way to see the format of the Eudora Nicknames/Address Book file is to use Eudora to create some nicknames (if you haven't already) and then look at the file nndbase.txt. It is just an ASCII file, so you can view it with any text editor, word processor, or file viewer. It is recommended that you do this because the default Eudora format for Nicknames/Address Book (what Eudora writes when using the Make Nickname/Make Address Book Entry command) has quietly changed with various changes in Eudora versions. In some versions of Eudora the format is identical to the format used for aliases in the .mailrc file that is probably familiar to those who have worked on Unix systems; in other versions the format is a slight variation on that format. In any event, it appears that Eudora has no problem accepting several formats. However, some of the conversion utilities for transforming Eudora Nickname/Address Book files into other address book formats are not as forgiving as Eudora. As of Eudora 3.0 beta 15, the basic Eudora default format is:

alias Nick_Name Real Name <email@address>

For Nicknames that include multiple recipients (mailing lists), the recipients are separated by commas, like so [sorry if you have to scroll horizontally to see this, but I want to keep it on one line, just like Eudora requires in the Nicknames/Address Book files]:

alias Nick_Name Real Name <email@address>,Nicholas_Moniker_MD Dr. Nicholas Moniker <email2@address>,etc.

Some things to remember:

There are at least four important things to note:

The Real Name part is optional. You do not have to include it.

The quotation marks (inverted commas in UK-speak) surrounding "Nick Name" are quasi-optional. If there are any embedded spaces, commas, or other punctuation in the Nickname, then quotation marks are required. Otherwise, you don't need them, but it does no harm to include them. For example, both of these are vaild for the Nickname "Control":

alias Control Agent 86 <MSmart@control.org>, Agent 99 <agent99@control.org>, Chief Chief <thadeus@control.org>
alias "Control" Agent 86 <MSmart@control.org>, Agent 99 <agent99@control.org>, Chief Chief <thadeus@control.org>

but this is not valid for the Nickname "Control Agents":

alias Control Agents Agent 86 <MSmart@control.org>, Agent 99 <agent99@control.org>, Chief Chief <thadeus@control.org>

Instead, it would have to be:

alias "Control Agents" Agent 86 <MSmart@control.org>, Agent 99 <agent99@control.org>, Chief Chief <thadeus@control.org>

alias Control_Agents Agent 86 <MSmart@control.org>, Agent 99 <agent99@control.org>, Chief Chief <thadeus@control.org>

On Nicknames with multiple addresses, they must be separated in nndbase.txt (or other Nicknames/Address Book file for those using multiple Nicknames/Address Book files) with commas. In the Eudora Nicknames/Address Book dialog window you can use commas OR carriage returns, but the Nickname file itself you must use commas only. When you use carriage returns in the Eudora dialog Eudora translates them to commas when it writes the Nicknames/Address Book file.
Eudora is more liberal than .mailrc files in the format of aliases it will interpret. I have not tried all of the possible variations to see what works. What I have described above is consistent with the default format the Eudora uses when creating a Nickname using the Special / Make Nickname menu option. At least I think so ;o)
I do know that the following are also among the formats accepted by Eudora. At least one of them was the default format from Eudora's Make Nickname command in earlier versions of the program, so if you have been using Eudora for some time you might have some of these in your nndbase.txt or other Nicknames/Address Book files. I know I do.
```
alias "Agent 86" MSmart@control.org (Maxwell Smart)
alias "Agent 86" MSmart@control.org (Maxwell Smart), "Agent 99" agent99@control.org (Barbara Feldon)
alias Chief Chief <Chief@control.org>
alias Chief <Chief@control.org>
alias Chief Chief@control.org
```

What about the nndbase.toc file?

The nndbase.toc file (and other .toc files associated with other Eudora Nicknames/Address Book files) is like the .toc files for Eudora mailboxes. More specifically:

It contains some kind of indexing information for the nndbase.txt file.
It is not plain ASCII text and it was not designed to be edited by humans, but rather by the Eudora program itself.
If it is deleted, Eudora will build a new one for you.

Tip: Whenever you edit the nndbase.txt (or other Nickname file) outside of Eudora, you should delete the corresponding .toc file and make Eudora re-build it, so they stay synchronized.

If you want to create your own Address Book .toc file, rather than having Eudora create it, Nick Spalding has done some research on the .toc file format for Address Book/Nickname files, and reports the following:

      It is really very simple, at least for Light it is.  I've 
      no idea if Pro is more complicated but I don't think it 
      can be as otherwise one wouldn't be able to switch so
      easily from one to the other.  Each entry consists of a
      CR/LF delimited name followed by 16 bytes of binary data 
      which are:

      Offset    Type  Content

      0         LONG  Offset within nndbase.txt of first byte of Address
      4         LONG  Length of Address
      8         LONG  Offset of nndbase.txt of first byte of Note if present
                      otherwise -1
      12        LONG  Length of Note if present otherwise -1


      Note these are offsets in the .txt, i.e., the first byte i the file
      is considered as byte zero.

One final tip about Eudora Nicknames/Address Book:

When making a mailing list, first create individual nicknames for everyone on the mailing list, then use that nickname, and not the email address for that person in the group or mailing list Nickname. Here is an example:

alias Agent_86 MSmart@control.org (Maxwell Smart)
alias Agent_99 Agent99@control.org (Barbara Feldon)
alias Chief Chief@control.org (Chief)
alias Control Agent_86,Agent_99,Chief

That way, when someone changes email addresses, you only have to edit the individual entry, and all of the mailing lists that person is on will be automatically updated, because they refer to the individual's Nickname entry to pick up the real email address.

Return to top of this page Return to Ken's Eudora Resources Page

This page has had hits since August 14, 1996.
Counter courtesy of George Burgyan